ツチヤ　ケン   TSUCHIYA Ken   土谷　健    所属   医学部 医学科（東京女子医科大学病院）    職種   客員教授
言語種別	英語
発表タイトル	Investigation of the Serum Ferritin Thresholds Necessary for Erythropoiesis and Iron Sufficiency in Patients on Hemodialysis
会議名	Kidney Week 2025
主催者	American Society of Nephrology
学会区分	国際学会及び海外の学会
発表形式	ポスター掲示
講演区分	一般
発表者・共同発表者	◎Ogawa Chie, Tsuchiya Ken, Morito Taku, Maeda Kunimi
発表年月日	2025/11/07
国名	アメリカ合衆国
開催地 （都市, 国名）	Houston, USA
開催期間	2025/11/05～2025/11/09
概要	Background We previously reported that total body iron (TBI), defined as the sum of RBC iron and iron stores, reflects iron sufficiency during oral iron therapy, where absorption is suppressed by mucosal block once stores are replete. Serum ferritin (Ft) is commonly used as a guide for iron supplementation in hemodialysis (HD) patients, but Ft level indicating iron sufficiency and the amount needed for effective erythropoiesis remain unclear. Methods We analyzed data from 101 OIRT courses in 79 HD patients. OIRT was initiated when Ft was <60 ng/mL and Hb <12 g/dL, and continued for at least seven months. Target Hb was 10–12 g/dL per Japanese guidelines. To examine the relationship between changes in Hb and ferritin (ΔHb, ΔFt) from 4 months (4M; point of TBI stabilization) to 7 months (7M), a multivariable linear regression analysis was performed, adjusting for changes in TBI (ΔTBI). Additionally, Bonferroni correction was applied for multiple comparisons of mean values at 0, 4, and 7 M. Results This study analyzed 101 OIRT courses in 79 HD patients. Median age and dialysis vintage were 70.7 and 7.2 years, respectively. Of the 101 OIRT courses, 74 were in male patients, and 33.7% had diabetic nephropathy. Hb showed a significant increase by 4M, followed by a slight downward trend at 7M. Ft levels increased significantly through to 7M. There was a significant inverse association between ΔHb and ΔFt (β = –36.9; 95% CI: -40.1 to -31.7; R2 = 0.76; P <0.01) (Fig. 1). The median Ft at 4M was 57.5 ng/mL (IQR: 37.8–74.1). A significant inverse correlation was also observed between ΔHb and Ft at 7M (P < 0.01), indicating that increases in Ft at 7M were associated with decreases in Hb. When ΔHb was 0 g/dL, the estimated serum ferritin was 68.0 ng/mL (95% CI: 60.1–75.8; P < 0.01). Conclusion This study suggests that an increase of 1 g/dL in Hb requires approximately 30–40 ng/mL of Ft. Furthermore, during Hb stability, a Ft level of approximately 40–80 ng/mL may indicate iron sufficiency.